Hub-pulling apparatus



1967 o. TORLAY HUB-PULLING APPARATUS Filed Oct. 27, 1966 IN VEN TUR. DWIGHT L. TORLAY y A I forn ey United States Patent 3,334,404 HUB-PULLING APPARATUS Dwight L. Torlay, Trenton, N.J., assignor to United States Steel Corporation, a corporation of Delaware Filed Oct. 27, 1966, Ser. No. 589,941 1 Claim. (Cl. 29-252) ABSTRACT OF THE DISCLOSURE This invention relates to apparatus for pulling shrunkfitted gears, coupling hubs, or other machine parts from shafts. The invention is particularly useful Where the gears or other machine parts to be pulled are of such a small size that the conventional apparatus for pulling shrunk-fitted machine parts cannot be attached and used without damaging the part.

In the prior art, a hydraulic jack has been-attached to the part to be pulled by means of a collar surrounding the part, a yoke attached to the jack, and long bolts connected between the yoke and the collar. By this invention, a plate with counterbored holes is attached to the jack and bolted flush against the machine part with bolts that are inserted in the counterbored holes and threaded into tapped holes in the machine part.

Conventional means for pulling machine parts from shafts have usually consisted of a hydraulic jack that has its outer body connected to a collar that fits over and engages the back side of the machine part to be pulled. The jack has a movable ram head that slides within the body and engages the end face of the shaft. The pressure means of the jack forces the ram head to push the shaft backward relative to the machine part.

In the attachment of the main body of the jack to the collar surrounding the machine part, a yoke is often attached across the front face of the jack, and a hole is provided in the center of the yoke for passage of the ram through the jack and against the end face of the shaft. The yoke is bolted to the machine part to be removed by long bolts that are held in slots in the yoke. The slots extend lengthwise and inwardly from either end of the yoke, and permit the bolts to be positioned for various sizes of collars and machine parts to be removed.

There are several difficulties with this conventional apparatus. The collar that fits over the machine part frequently comes into contact with the gear teeth or other projections on the cylindrical surface of the part. As the part is pulled off the shaft, the collar rubs against it, causing abrading and chipping.

Another difficulty is that there is some bending of the bolts in the space between the collar and the yoke, causing a force on the machine part being removed that is not exactly parallel with the axis of the shaft. This makes the part more difficult to remove and increases the likelihood of it being damaged.

Still another difficulty with the conventional apparatus is that it cannot be used to pull the smaller diameter machine parts from their shafts. This is because the bolts which fit in the slots in the yoke cannot be brought close enough together for these smaller parts. The bolt heads are on the same side of the yoke as the jack and their spacing is limited by the size of the jack that is attached to the central part of the yoke. The force required to remove these smaller machine parts requires a jack that is of a very large diameter compared to the diameters of the machine parts and shafts to be separated.

Thus, an object of my invention is to provide apparatus for pulling shrunk-fitted machine parts from shafts that will be free of the foregoing difficulties of prior apparatus.

3,334,404 Patented Aug. 8, 1967 This and other objects will appear more readily from the following detailed description of my invention and the attached drawings, in which:

FIGURE 1 is a longitudinal section of apparatus for pulling a coupling hub from its shaft, taken along line I--I of FIGURE 2;

FIGURE 2 is a section of the apparatus of FIGURE 1, taken along line II-II of FIGURE 1; and

FIGURE 3 is a right hand end view of one of the parts of the apparatus of FIGURE 1.

In FIGURE 1, a coupling hub H with its outer sleeve L is shown mounted on a shaft S. A hub-pulling apparatus 2 is mounted on the right hand end of hub H and includes a hydraulic jack 4 with a slidable ram head 6.

To secure the main body of the jack. 4 to the hub H, an adapting plate 8 is secured to the right hand end of hub H by bolts 10. The bolts 10 are housed in counter bored holes 12 of plate 8 and are threaded into tapped holes 14 of the hub H. Hexagonal holes 15 in the heads of bolts 10 (FIGURE 2) permit the bolts to be tightened by an Allen wrench until the plate 8 is flush against the end surface of the hub H, with the heads of bolts 10 being housed completely inside the enlarged portions of the counterbored holes 12.

After the adapting plate 8 is bolted to the hub H, an adapting sleeve 16 is bolted to the plate 8. The sleeve 16 is a conventional part supplied by most hydraulic jack manufacturers. Because of the relatively small size of the hub H compared to the jack which must be used to pull it off, the sleeve 16 partially covers the heads of bolts 10 in the counterbored holes 12. The jack 4 should be capable of developing a maximum force of 40 to 50 thousand pounds, and the adapting sleeve 16 provided by Snap-On Tool Company for their jacks of this size has a 4% inch outside diameter. This sleeve would partially cover the heads of bolts 10 having center lines spaced as far apart as 5 /2 inches.

The sleeve 16 is secured to the plate 8 by bolts 18, which are housed in three counterbored holes 20 in sleeve 16 (FIGURE 3) and which threadably engage tapped holes 22 in plate 8. The bolts 18 are tightened by an Allen wrench that fits into holes 24 in the heads of the bolts. The adapting sleeve 16 is threaded internally at its right hand end to permit the externally threaded portion 25 of the main body of the jack 4 to be connected to the sleeve.

While the jack 4 is thus connected to the hub H by plate 8 and sleeve 16, the ram head 6 of the jack 4 passes through a large opening 26 in plate 8 and engages the end face F of shaft S (FIGURE 1). As the ram head 6 is pressed forward against the shaft 8 the hub H is pulled backward until it is removed from the shaft. Because the hub H is bolted flush against the surface of plate. 8, the pulling force on the hub is steady and remains parallel to the axis of shaft S.

The face of plate 8 adjacent sleeve 16 is shown in FIG- URE 2. In order that the plate 8 be useful with different sizes of hubs H, a number of pairs of counterbored holes 12, 12a, 12b and are drilled in the plate 8 for housing different sizes of bolts 10, spaced various distances apart from each other. It is usually possible to drill in one plate 8 enough pairs of holes to make the plate useful with an entire line of coupling hubs, gears or other machine parts that are made by a single manufacturer.

It is thus apparent that with my invention, a hydraulic jack can be attached securely to any size of coupling hub or other machine. part, no matter how small. The attachment can be made quickly and easily by first bolting the adapting plate 8 to the machine part to be removed, then bolting the adapting sleeve 16 to the plate 8, and then screwing the jack 4 onto the rear end of sleeve 16. This results in a sturdy attachment, whereby the machine part 3 can be pulled off of its shaft smoothly and without abrasion or other damage to the part.

While I have thus shown and described one embodiment of my invention, other adaptations and modifications will be apparent within the scope of the appended claim.

I claim:

Apparatus for pulling from a shaft a machine part that has been shrunk-fitted to said shaft and has at least two tapped holes with axes parallel to the aXis of said ahaft, said apparatus comprising (a) a plate placed against an end of said shaft having (1) an opening therethrough exposing part of said end of the shaft and (2) at least two bolt holes extending through the plate and aligned with said tapped holes in said shrunk-fitted machine-part,

(3) said holes having enlarged portions on the side of said plate facing away from said shaft and shrunk-fitted machine part,

(b) at least two bolts placed through said bolt holes and threadably engaged in said tapped holes of said machine part, the heads of said bolts being fully within the enlarged portions of saidbolt holes,

(c) an adapting sleeve having a central opening and placed against said plate with said central opening in alignment with said opening in said plate, said adapting sleeve covering at least part of the heads of said bolts,

(d) additional bolts securing said adapting sleeve to said plate, said additional bolts having their heads facing away from said end of said shaft,

(e) and a jack means having its main body connected to said adapting sleeve and a movable ram passing through said openings of said adapting sleeve and said plate and engaging said end of said shaft, said jack means being equipped with means for pressing said ram against said end of said shaft and moving saidshaft relative to said shrunk-fitted machine part.

References Cited UNITED STATES PATENTS 1,488,020 3/1924 Malone 29252 1,721,189 7/1929 Schekall et al 29252 2,003,756 6/1935 Nagel 29252 2,488,476 11/1949 Pine 29252 2,490,284 12/1949 Simart 29252 X WILLIAM FELDMAN, Primary Examiner.

MYRON C. KRUSE, Examiner. 

